This application claims benefit of Japanese Application No. H11-147086 filed in Japan on May 26, 1999, the contents of which are incorporated by this reference.
1. Field of the Invention
This invention relates to a camera provided with a barrier, and more particularly to a camera provided with a barrier which covers a picture-taking lens.
2. Related Art Statement
Recently, in the field of compact cameras, to satisfy demands on contours or design while taking into account the protection of picture-taking lenses and the portability of cameras, cameras which cover the front faces of these picture-taking lenses by means of slide-type barriers with retractable lens barrels in camera bodies have been commercialized.
With respect to the cameras provided with these slide barrier mechanisms, from the viewpoint of design, it is desirable that the surface of the slide barrier and the front surface of the camera body become approximately coplanar when the slide barrier is closed so as to cover the picture-taking lens.
Japanese Laid-Open Patent Publication 163938/1983 discloses a camera which takes such a viewpoint into consideration. In this camera, on upper and lower portions of a front surface of a camera body, cam grooves which are composed of a groove which perpendicularly intersects an optical axis direction of the picture-taking lens (a perpendicularly intersecting groove) and two grooves which are bent in the optical axis direction relative to the perpendicularly intersecting groove (the groove at the distal end side constituting a first optical axis groove and the groove branched from the middle portion of the perpendicularly intersecting groove constituting a second optical axis groove) are disposed. Further, the camera is provided with a slide barrier which slides along these cam grooves. On the upper and lower portions of the slide barrier, two pins which are slidably fitted into the cam grooves are respectively provided. That is, four grooves in total are provided on the upper and lower portions of the slide barrier.
These two pins (the pin disposed at a position close to the center constituting the first pin and the pin disposed close to the side constituting the second pin when the slide barrier is held in the opened position) are disposed corresponding to the above-mentioned two optical axis grooves (the first and second grooves). Then, at the time of closing the slide barrier, the first and second pins are moved from the perpendicularly intersecting groove to the first and second optical axis grooves. As a result, the slide barrier is moved toward the rear portion of the camera so as to make the front surface of the slide barrier substantially coplanar with the front surface of the camera body.
In the camera disposed in Japanese Laid-Open Patent Publication 163938/1983, it is basically intended that, at the time of closing the slide barrier, the first pin which is disposed close to the center moves to the distal-end-side first optical axis groove and the second pin which is disposed close to the side moves to the branched second optical axis groove. However, in case a gap between wall portions of the camera which guide the slide barrier and the slide barrier itself is large, in the course of the movement of the slide barrier, the first pin enters the branched second optical axis groove which is disposed ahead of the first axis groove and hence, it gives rise to a problem in which the slide barrier cannot be closed smoothly, thus deteriorating the usability of the camera.
It is the first object of the present invention to provide a camera having a barrier of simple constitution and yet having a favorable usability.
It is the second object of the present invention to provide a camera which ensures a smooth operation in opening or closing the slide barrier by skillfully determining the width of a plurality of cam grooves and the diameter of cam followers which are engaged with these grooves.
In summary, with respect to the camera of the present invention, a first cam groove and a second cam groove which is branched from the middle portion of the first cam groove and has a width narrower than a width of the first cam groove are provided on a camera body, a first cam follower having a diameter which corresponds to the width of the first cam groove and a second cam follower having a narrow diameter which corresponds to the width of the second cam groove are provided on a slide barrier, and at the time of moving the slide barrier from an opened position to a closed position at which the slide barrier covers a picture-taking lens, the first cam follower is prevented from entering or intruding into the second cam groove having the narrow width and to thus slide smoothly along the first cam groove.
These objects and advantages of the present invention will become further apparent from the following detailed explanation.